$(document).ready(function(){
	
	windowSizeCal();
});


function windowSizeChange(){
	windowSizeCal();
}


//窗口居中计算
function windowSizeCal(){
	var h1 = $(".firstRegion").height();
	var h2 = $(".secondRegion").height();
	var h3 = $(".threeRegion").height();
	
	$(".secondRegion").css("margin-top",(h1-h2)/2);
	$(".threeRegion").css("margin-top",(h1-h3)/2);
}